Electrodepostion of metals from liquid media

Abstract

Disclosed are methods for direct electrodeposition of a metal from the liquid medium. The methods include electro-reduction of lithium anions on cathode electrodes in the presence of various metal deposition selectivity enhancements. The selectivity enhancement disclosed herein comprises the presence of a magnet, a solvent that is immiscible with an original liquid medium comprising the desired metal ions or various separators. Also disclosed are systems for electrodeposition of the desired metals from the liquid medium.

What is claimed is: 
     
       1. A method comprising:
 selectively recovering a metal from a liquid medium comprising metal ions of lithium, sodium, magnesium, calcium, potassium, barium, or one or more rare earth elements, or any combination thereof by 
 applying a voltage to an electrochemical cell comprising the liquid medium, an anode and a cathode to induce an electric current flow from the anode to the cathode, wherein the voltage is effective to induce a selective reduction of the metal ions on the cathode; 
 applying a magnetic field directed orthogonally to the electric current flow to induce an azimuthal motion of the liquid medium, thereby rotating the liquid medium around the cathode; 
 forming a selective centrifugal partitioning of metal ions towards the anode and cathode based on a mass-to-charge ratio of the metal ion; 
 depositing a selectively reduced metal on the cathode; and 
 recovering the selectively reduced metal with a yield from about 20% to about 100%. 
 
     
     
       2. The method of  claim 1 , wherein the liquid medium comprises an aqueous solution, an organic solution, a nonaqueous solution, or a combination thereof. 
     
     
       3. The method of  claim 1 , wherein the metal comprises lithium, sodium, magnesium, calcium, potassium, barium, one or more rare earth elements, or alloys thereof. 
     
     
       4. The method of  claim 1 , wherein the metal ions are present in an amount of less than about 2,000 ppm in the liquid medium. 
     
     
       5. The method of  claim 1 , wherein the selectively reduced metal forms a plurality of fractal dendrites, a mossy structure, a needle-like structure, or a combination thereof on the cathode. 
     
     
       6. The method of  claim 1 , wherein the anode and cathode are disposed concentrically such that the anode is positioned around the cathode at a radial distance, and wherein the electric current flow is a radial current flow. 
     
     
       7. The method of  claim 1 , wherein the magnetic field induces a continuous advection of the liquid medium and/or the magnetic field forms an electromagnetic centrifuge. 
     
     
       8. The method of  claim 1 , wherein the voltage is from about −5V to about 5 V and/or wherein the magnetic field is applied at from about 1 MT to about 0.2 T. 
     
     
       9. The method of  claim 1 , wherein the electrochemical cell further comprises a further solvent that is substantially immiscible with the liquid medium and is in flow communication with the cathode. 
     
     
       10. The method of  claim 9 , wherein the further solvent is an organic solvent that is selective to the metal to be deposited and comprises dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, polyoxylene, propylene carbonate, fluoroethylene carbonate, ethylene carbonate, room-temperature ionic liquids, or any combination thereof. 
     
     
       11. The method of  claim 10 , wherein the organic solvent further comprises one or more metal selectivity improving additives comprising a chelating agent, TiO 2 , or any combination thereof. 
     
     
       12. The method of  claim 9 , further comprising disposing a separator, wherein the separator is substantially permeable and selective to the metal ions and is configured to partition the further solvent from the liquid medium and wherein the separator comprises a metal-organic framework (MOF), polyethylene terephthalate membrane, cellulose acetate butyrate), polysulfone, polybenzimidazole, poly(amideimide), polyethersulfone, polyphenylsulfone, polyimide, polyacrylonitile, poly(ethylene oxide), poly(ether ether ketone), poly(vinylidene fluoride), poly(ethylene chlorotrifluoroethylene), polycarbonate, polystyrene, poly(ether-block-amide), acrylonitrile butadiene styrene, bisphonenolsulfone, carbon nanotubes, or derivatives and combinations thereof. 
     
     
       13. The method of  claim 1 , wherein the liquid medium is a geothermal brine, produced waters, wastewater, recycled batteries' electrolytes, seawater, desalination brines, aquifer brines, or any combination thereof. 
     
     
       14. The method of  claim 1 , wherein the cathode comprises copper, carbon, graphite, sodium, lithium, λ-MnO 2  and LiMn 2 O 4  spinel, olivine LiFePO 4  and FePO 4 , or layered LiNiMnO 2 , and/or the anode comprises carbon or platinum. 
     
     
       15. The method of  claim 1 , wherein the selectively deposited reduced metal has a purity from greater than 20% to 100%. 
     
     
       16. A method comprising:
 selectively recovering a metal from a liquid medium comprising metal ions of lithium, sodium, magnesium, calcium, potassium, barium, or one or more rare earth elements, or any combination thereof by 
 applying a voltage to an electrochemical cell comprising the liquid medium, an anode and a cathode to induce an electric current flow from the anode to the cathode, wherein the voltage is effective to induce a selective reduction of the metal ions on the cathode; 
 applying a magnetic field directed orthogonally to the electric current flow; 
 forming a selective centrifugal partitioning of metal ions towards the anode and cathode based on a mass-to-charge ratio of the metal ion; 
 depositing a selectively reduced metal on the cathode; and 
 recovering the selectively reduced metal with a yield from about 20% to about 100%. 
 
     
     
       17. The method of  claim 1 , wherein the selectively reduced metal is Li. 
     
     
       18. The method of  claim 17 , wherein any metal ions having a mass-to-charge ratio higher than 1×10 −4  g/C are not reduced. 
     
     
       19. The method of  claim 1 , wherein a metal recovery rate is greater than 5 g/cm 2  in 100 hours. 
     
     
       20. The method of  claim 1 , wherein the liquid medium has a pH that is acidic, basic, or neutral. 
     
     
       21. A method for selective recovery of a metal from a liquid medium comprising ions of the metal wherein the method comprises:
 applying a voltage to an electrochemical cell comprising the liquid medium, an anode and a cathode to induce an electric current flow from the anode to the cathode, wherein the voltage is effective to induce a reduction of the metal ions on the cathode; 
 wherein the electrochemical cell comprises a separator, wherein the separator is substantially permeable and selective to the metal ions and wherein the separator comprises a metal-organic framework (MOF), polyethylene terephthalate membrane, cellulose acetate butyrate), polysulfone, polybenzimidazole, poly(amideimide), polyethersulfone, polyphenylsulfone, polyimide, polyacrylonitile, poly(ethylene oxide), poly(ether ether ketone), poly(vinylidene fluoride), poly(ethylene chlorotrifluoroethylene), polycarbonate, polystyrene, poly(ether-block-amide), acrylonitrile butadiene styrene, bisphonenolsulfone, carbon nanotubes, or derivatives and combinations thereof; 
 applying a magnetic field directed orthogonally to the electric current flow to induce an azimuthal motion of the liquid medium, thereby rotating the liquid medium around the cathode; 
 depositing a reduced metal on the cathode; and 
 recovering the reduced metal. 
 
     
     
       22. A method for selective recovery of a metal from a liquid medium comprising ions of the metal wherein the method comprises:
 applying a voltage to an electrochemical cell comprising the liquid medium, an anode and a cathode to induce an electric current flow from the anode to the cathode, wherein the voltage is effective to induce a reduction of the metal ions on the cathode; 
 wherein the electrochemical cell further comprises a further solvent that is substantially immiscible with the liquid medium and is in flow communication with the cathode and a separator, wherein the separator is substantially permeable and selective to the metal ions and is configured to partition the further solvent from the liquid medium and wherein the separator comprises a metal-organic framework (MOF), polyethylene terephthalate membrane, cellulose acetate butyrate), polysulfone, polybenzimidazole, poly(amideimide), polyethersulfone, polyphenylsulfone, polyimide, polyacrylonitile, poly(ethylene oxide), poly(ether ether ketone), poly(vinylidene fluoride), poly(ethylene chlorotrifluoroethylene), polycarbonate, polystyrene, poly(ether-block-amide), acrylonitrile butadiene styrene, bisphonenolsulfone, carbon nanotubes, or derivatives and combinations thereof; 
 applying a magnetic field directed orthogonally to the electric current flow to induce an azimuthal motion of the liquid medium, thereby rotating the liquid medium around the cathode; 
 depositing a reduced metal on the cathode; and 
 recovering the reduced metal.